Apparatus for the acoustic-ambience conditioning of a medium



Aug. 20; 1963 Filed Feb. 15, 1961 CONDITIONING OF A MEDIUM 2 Sheets-Sheet 1 0 Fl 1 POWER REGULATING SIGNAL GENERATOR DEVICE MICROPHONE INPUT STAGE 1 FLIP-FLOP RELEASE LEVEL I 3 ADJUSTMENT DEVICE 3 1 d FLOP FLOP A' Io 6 v V t to m T t2 113T M 1 E1 E 2 E 1 JIVI/ENTOE ALFRED fM/GE ANGUS 7'6 IBM/177$ ma, 44m, Wm; M,

Aug. 20, 1963 A. A. A. TOMATIS I APPARATUS FOR THE ACOUSTIC-AMBIENCE CONDITIONING OF A MEDIUM Filed Feb. 15, 1961 2 Sheets-Sheet NmA I- EEK r I n .u .I. m -L -::---L--F-:- -L 1 Q I l I i 1 =5 I L; I

United States Patent APPARATUS FOR THE ACOUfiTIC-AMBRENCE CONDKTIGNING 9F A MEDHUM Alfred Ange Auguste Tomatis, Paris, France, assignor to Societe ivile dEtudes et de Brevets Meta, Paris, France Filed Feb. 15, 1961, Ser. No. $9,512 Claims priority, application France Feb. 15, 1960 7 Claims. (Ci. 1791) The present invention relates to an apparatus adapted to achieve the acoustic conditioning of a medium.

It has been noted that audition is variable in tunction in accordance with the state of the ambient medium. This medium, although providing no measurable sensations by itself, gives none the less rise to a plurality of controllable physiological reactions. This explains the feeling of comfort experienced in a reverberant room and the feeling of oppression in an echo-less or dead surround The pleasing sensation of reverberant rooms is due to the relative suppression of the low pitched sounds, [or rather to the predominance of the high-pitched sounds with respect to lovvapitched sounds.

It is thereiore an object of the present invention to provide a background of acoustic ambience on which the noise, the sound activity and, especially the phonation of the persons present will be superposed.

According to the invention, the method of acousticambience conditioning of a given medium comprisesz-prearranging said medium in a (first state of acoustic ambience when in its initial rest position, i.e. with no acoustic signal being of an intensity higher than a given threshold, then, upon occurrence of a signal having an intensity exceeding said threshold, causing said medium to switch from said first state of acoustic ambience to a second state of such ambience, and, finally, restoring the medium to the first state of acoustic ambience, upon disappearance of said signal. 1

According to a feature of the invention, the passage from the first to the second state of acoustic ambience is repeated periodically, as many times as required.

The acoustic signal causing the passage from the first to the second state of acoustic ambience may be derived either from an external source, for example a tape recorder, or else it may be the voice of thesubject himselt present in the medium.

In each one of said two states of acoustic ambience, a selected ambience may be superposed to the medium, at will. As soon as the acoustic signal-sound or noise reaches a certain magnitude which is a function of a predetermined selected threshold, the first state of acoustic ambience will quiclcly vanish to make room to the second state of acoustic ambience.

The invention has also for its object an apparatus for carrying out the method of ambience-acoustic conditioning as outlined hereinabove.

The timing of the switching from the first to the second state of acoustic ambience may be adjusted at will.

The apparatus of the invention may be used in a plurality of applications. It is thus possible to provide more or less resonant ambiences of a desired level or more or less damped surroundings. Acoustical conditions may thus be provided particularly adapted to a foreign language, \for instance a condition adapted to the French or English language, etc. The adaptation and the auditive conditioning of the subjects present in themedium will then automatically result therefrom.

If an acoustic ambience of euphoric character is created, the subject placed in said ambience may then undergo a toning-up treatment. The creation of conditions :or ambiences of maximum relaxation may thus be achieved, or also the creation of conditions dififering from those in which the subject is accustomed to live in.

The apparatus of the invention may be adapted to a rational use of all kinds of rooms by providing the means rendering them acoustically pleasant to live in.

With the foregoing and other objects in view, the invention resides in the novel arrangement and combination of parts, and in the details of construction and embodiment hereinafter described and claimed, it being understood that changes in the precise embodiments of the invention herein disclosed may be made Within the scope of what is claimed without departing from the spirit of the invention. Other objects and advantages will become apparent from the following description taken in conjunction with the accompanying drawings in which:

FIGURE 1 is a diagram showing the principle of the apparatus of this inventiom. I

FIGURES 2(A) to 2(C) are diagrams illustrating the operation of the apparatus;

FIGURE 3 is a wiring diagram of a typical term of embodiment of the invention.

The various component elements of the apparatus of this invention areshown in block form in FIG. 1, these blocks being also shown in the detailed diagram of FIG. 3 in which they are designated by the same reference numerals.

In FIG. 1 the apparatus is shown as comprising essentially an input stage 1, a first channel 10 and another channel 2% connected in parallel, and an auxiliary channcl 30. Each one of these main elements is enclosed in dotted rectangles.

The input stage 1 comprises a microphone 3 receiving the acoustic signals, sounds or noise, emitted from an external source or from the subject himself or herself. 'Ilhis microphone is connected to a preamplifier 4 connected in turn to a general amplifier 6 thr'o gh a device 5 for adjusting the sensitivity of the microphone.

The output of amplifier '6 is connected to an impedancematching amplifier 7 having its output connected in parallel tothe inputs of channels 10 and 20. I An electric signal generator 55 is located in parallel relationship with said input stage; this generator being either a blank noise generator, a tape recorder or any other type of generator and connected, through a power regulating device 56 to the input of the impedance-matching amplifier 7.

The first channel 10 comprises in succession a device 11 for adjusting the gain of this channel, an amplifier 12, a filter 13 of which the response curve is adjustable by means of a knob 14, and finally a gate 15. Similarly, the other channel 21) comprises a gain adjustment device 21, an amplifier 22, a filter 23 of which the response curve is adjustable by means of a knob 24, and a gate 25.

The outputs of gates 15 and 25 are connected to one another at the input of a first output stage comprising an amplifier 141, a power regulating device 142 and a loud-speaker 143.

The output of filter 23 of channel 20 is directly connected to the input of a second output stage including an amplifier 151, a power regulating device 152 and a loud-speaker 153.

The auxiliary channel 30' has its input connected to the output of the general, amplifier 6 of input stage 1. This auxiliary channel 30 comprises in succession a device 31 for adjusting the flip-flop release level, an impedance adapting amplifier 32, a detector 33 and a device 3 4 for adjusting the time constant of the flip-flop 35 controlling the channels 10 and 20. The flip-flop 35 maybe of any known type and this specific application consists of a monostable multi-vibra-t-or of which the two outputs 35a and 35b are connected through conductors 36 and 37 respectively to the control inputs of gates 15 and 25 of channels 10 and 20'.

The operation of the apparatus of this invention will now be described with specific reference to FIGS. 2(A) to 2(C).

Assuming that in the initial state, that is at the time t the acoustic intensity of the input signal received by the microphone 3 is not sufiicient to release the monostable multivibrator 35. This corresponds to a first acoustic ambience state E the latter remaining from time t to time t FIG. 2(A) shows an acoustic signal 50 of rectangular shape, to indicate the noise or sound of which the intensity I is lower than the threshold 1 necessary for releasing the monostable multivibrator, this threshold being shown in the form of a dotted line at 51. The threshold of release of the monostable multivibrator 35 is determined by the device 31 for adjusting the level of the monostable multivibrator in combination with the detector 32. Therefore, by acting upon the device 31 it is possible to shift the threshold for which the multivibrator is released.

In this preliminary state corresponding to the first acoustic ambience state the multivibrator 35 is in its inoperative position. -In this position the output 35a connected to wire 36 has for example a positive voltage V (see FIG. 2(B) which opens the gate 15, the other gate being closed by the voltage V inferior to V (see FIG. 2(C), at which the output 35b connected to wire 37 has been brought.

Under these conditions, the first channel lit is released whereas on the contrary the other channel 20 is locked.

'In this initial state E all input signals derived on one hand from the electric signals produced by generator 55 and on the other hand from the acoustic signals of the medium considered, intercepted by microphone 3 and transformed by input stage 1, are simultaneously applied to amplifier 7 and pass through the first channel 16, which is thus uncl-amped. Under these conditions, these signals are modified as a function of the response curve of filter 13. This response curve may be selected at will to determine the first state of acoustic ambience E These signals are then transmitted via gate 15 to the first output stage 140, so that loud-speaker 143 emits acoustic signals modified according to the response curve of filter 13.. v

Simultaneously, all input signals are partially trans mitted through the second channel 20*, i.e. the signals are arranged to pass through filter 23 and are consequently modified in accordance with the response curve of said filter, in view of their being subsequently applied to the second output stage 150, wherein the loud-speaker 153 transmits acoustic signals modified in accordance with the response curve of filter 23.

The first state E is maintained up to the time t where an acoustic signal 52 appears which is shown in the form of a rectangular signal the intensity of which exceeds the threshold of release I of the monostable multivibrator 35. The signal may for example be emitted by the subject in the microphone 3. At the time t the detector 33 of the auxiliary channel 30 permits the passage of a launching signal transmitted (through the device 34 for adjusting the time constant) to the mul'tivibrator 35. The latter is thus triggered and moves to its operative state after a time T determined by the device 34 for adjusting the time constant. As a result, the control voltages applied to conductors 36 and 37 vary as indicated by the relevant curves of FIGS. 2(B) and 2(C). Therefore, it will be seen that after a time lapse T the gate 25 is fully open due to the voltage V applied to the input thereof, whilst on the contrary the gate 15 is fully closed due to the voltage V From this moment on the second channel 28) is released whereas the first channel is locked.

In this second state E all input signals are transmitted exclusively by the second channel 20 and are modified by filter 23 in accordance to the response curve thereof. The

signals, thus modified, are then transmitted simultaneously in parallel relationship with the response curve of filter 23.

If for certain particular applications, loud-speakers 143 and 153 are designed, respectively, to emit low-pitched and high-pitched sounds, the low-pitched sounds are modified in the first state of acoustic ambience E by the curve of filter 13, whereas the high-pitched sounds are modified by the response curve of filter 23. On the other hand, upon occurrence of the acoustic signal of an intensity exceeding the triggering threshold, the apparatus is switched into the second state, wherein the loud-speaker 143 of low-pitched sounds emits sounds modified by filter 23, this modification consisting, for instance, in an important attenuation of the low-pitched sounds, whereas the sounds emitted by loud-speaker 153 of the high-pitched sounds are modified in the same Way as in the first ambient state.

According to an alternative application of the method of the invention, the loud-speakers of the highand lowpitched sounds may be interchanged, and the high-pitched sounds in the second ambience state may be suppressed.

The acoustic ambience of the medium is thus periodically modified at each occurrence of an acoustic signal of sufficient intensity, such signal being, in fact, possibly, a sound emitted by the subject himself placed in said medium.

It is thus possible to transform at Will the acoustic ambience of any kind of room, while favoring the occurrence of certain desirable phenomena, as set forth hereinabove.

It is to be understood that the embodiment described and illustrated hereinabove is in no way limited by the example specified, many variations and modifications being possible, without departing from the spirit and scope of the invention.

What I claim is:

1. An apparatus for the acoustic ambience conditioning of a medium, comprising a first input stage for transforming the acoustic signals present in said medium into electric signals, an electric-signal generator corresponding to the background noise and operating continuously, two channels connected in parallel, the outputs of the generator and of the input stage being connected to one another at the. eonnnon input of these two channels, the first channel comprising a filter having a first response curve and a gate controlling the opening and closing of said channel, the second channel including a filter presenting a second response curve and a gate controlling the opening and closing of said second channel, a first output stage comprising means for transforming the electric signals into acoustic signals, the outputs of said two channels being connected to one another, at the input of said first output stage, a second output stage comprising means for converting the electric signals into acoustic signals, the output of the filter of said second channel being connected directly to the input of the second output stage, the apparatus being provided, in addition, with an auxiliary channel connected at the output of the input stage, said auxiliary channel comprising triggering means generating two control voltages applied, respectively to the gates of said first and said second channels, these control voltages being selected in such a manner that, in the absence of an acoustic signal of an intensity higher than a predetermined threshold, applied to the input stage, the first channel will be the only one to be unblocked, whereby the medium is placed in a first state of acoustic ambience wherein the input signals derived from a generator and from said input stage are transmitted to said first and said second output stages, respectively, via the filters of the first and second channels and that, when an acoustic signal of an intensity higher than said threshold is applied to the input stage, said first channel will thus be blocked, whereas said second channel will be unblocked, in such a manner that the input signals will then be transmitted to the two output stages, after having been modified, in the same Way, by the only filter of the second channel.

2. An apparatus according to claim 1, wherein the first output stage comprises a loud-speaker for low-pitched sounds, whilst the second output stage comprises a loudspeaker for the high-pitched sounds.

3. An apparatus according to claim 1, wherein the first output stage comprises a loud-speaker for the high-pitched sounds, whereas the second output stage comprises a loudspeaker for the low-pitched sounds.

4. An apparatus according to claim 1, wherein means are provided to vary the triggering time of said triggering means.

6 5. Apparatus according to claim 1, wherein means are provided for adjusting the triggering level of said triggering means.

6. An apparatus according to claim 1, wherein means are provided to separately vary the gain of each channel.

7. An apparatus according to claim 1, wherein means are provided for adjusting the sensitivity of the microphone at the input stage.

No references cited. 

1. AN APPARATUS FOR THE ACOUSTIC AMBIENCE CONDITIONING OF A MEDIUM, COMPRISING A FIRST INPUT STAGE FOR TRANSFORMING THE ACOUSTIC SIGNLS PRESENT IN SAID MEDIUM INTO ELECTRIC SIGNALS, AN ELECTRIC-SIGNAL GENERATOR CORRESPONDING TO THE BACKGROUND NOISE AND OPERATING CONTINUOUSLY, TWO CHANNELS CONNECTED IN PARALLEL, THE OUTPUTS OF THE GENERATOR AND OF THE INPUT STAGE BEING CONNECTED TO ONE ANOTHER AT THE COMMON INPUT OF THESE TWO CHANNELS THE FIRST CHANNEL COMPRISING A FILTER HAVING A FIRST RESPONSE CURVE AND A GATE CONTROLLING THE OPENING AND CLOSING OF SAID CHANNEL, THE SECOND CHANNEL INCLUDING A FILTER PRESENTING A SECOND RESPONSE CURVE AND A GATE CONTROLLING THE OPENING AND CLOSING OF SAID SECOND CHANNEL, A FIRST OUTPUT STAGE COMPRISING MEANS FOR TRANSFORMING THE ELECTRIC SIGNALS INTO ACOUSTIC SIGNALS, THE OUTPUTS OF SAID TWO CHANNELS BEING CONNECTED TO ONE ANOTHER, AT THE INPUT OF SAID FIRST OUTPUT STAGE, A SECOND OUTPUT STAGE COMPRISING MEANS FOR CONVERTING THE ELECTRIC SIGNALS INTO ACOUSTIC SIGNALS, THE OUTPUT OF THE FILTER OF SAID SECOND CHANNEL BEING CONNECTED DIRECTLY TO THE INPUT OF THE SECOND OUTPUT STAGE, THE APPARATUS BEING PROVIDED, IN ADDITION, WITH AN AUXILIARY CHANNEL CONNECTED AT THE OUTPUT OF THE INPUT STAGE, SAID AUXILIARY CHANNEL COMPRISING TRIGGERING MEANS GENERATING TWO CONTROL VOLTAGES APPLIED, RESPECTIVELY TO THE GATES OF SAID FIRST AND SAID SECOND CHANNELS, THESE CONTROL VOLTAGES BEING SELECTED IN SUCH A MANNER THAT, IN THE ABSENCE OF AN ACOUSTIC SIGNAL OF AN INTENSITY HIGHER THAN A PREDETERMINED THRESHOLD, APPLIED TO THE INPUT STAGE, THE FIRST CHANNEL WILL BE THE ONLY ONE TO BE UNBLOCKED, WHEREBY THE MEDIUM IS PLACED IN A FIRST STATE OF ACOUSTIC AMBIENCE WHEREIN THE INPUT SIGNALS DERIVED FROM A GENERATOR AND FROM SAID INPUT STAGE ARE TRANSMITTED TO SAID FIRST AND SAID SECOND OUTPUT STAGES, RESPECTIVELY, VIA THE FILTERS OF THE FIRST AND SECOND CHANNELS AND THAT, WHEN AN ACOUSTIC SIGNAL OF AN INTENSITY HIGHER THAN SAID THRESHOLD IS APPLIED TO THE INPUT STAGE, SAID FIRST CHANNEL WILL THUS BE BLOCKED WHEREAS SAID SECOND CHANNEL WILL BE UNBLOCKED, IN SUCH A MANNER THAT THE INPUT SIGNALS WILL THEN BE TRANSMITTED TO THE TWO OUTPUT STAGES, AFTER HAVING BEEN MODIFIED, IN THE SAME WAY, BY THE ONLY FILTER OF THE SECOND CHANNEL. 